The present invention relates to testing data packet signal transceivers with multiple radio access technologies, and in particular, to achieving faster test times for such transceivers by using interleaved device setup and testing.
Many of today's electronic devices use wireless technologies for both connectivity and communications purposes. Because wireless devices transmit and receive electromagnetic energy, and because two or more wireless devices have the potential of interfering with the operations of one another by virtue of their signal frequencies and power spectral densities, these devices and their wireless technologies must adhere to various wireless technology standard specifications.
When designing such wireless devices, engineers take extra care to ensure that such devices will meet or exceed each of their included wireless technology prescribed standard-based specifications. Furthermore, when these devices are later being manufactured in quantity, they are tested to ensure that manufacturing defects will not cause improper operation, including their adherence to the included wireless technology standard-based specifications.
For testing these devices following their manufacture and assembly, current wireless device test systems (also referred to as “testers”) employ a subsystem for analyzing signals received from each device. Such subsystems typically include at least a vector signal generator (VSG) for providing the source signals to be transmitted to the device under test, and a vector signal analyzer (VSA) for analyzing signals produced by the device under test. The production of test signals by the VSG and signal analysis performed by the VSA are generally programmable so as to allow each to be used for testing a variety of devices for adherence to a variety of wireless technology standards with differing frequency ranges, bandwidths and signal modulation characteristics.
As these types of wireless devices have become more sophisticated, they now often include transceiver circuitry that provides communications and connectivity based on multiple standards-based technologies, often referred to as radio access technologies (RATs), such as 4G LTE cellular, GSM, IEEE 802.11x WiFi, and Bluetooth, to name a few.
To fully test such devices capable of communicating using multiple RATs, each technology and its related transceiver circuitry must be tested against the appropriate standards-based specification for that technology. If these tests are carried out sequentially, overall test time can be several minutes, which is a long time when testing many thousands, and more often millions, of devices. One solution for reducing the per-device test time is to test several devices under test (DUTs) concurrently. For example, five separate test systems (often referred to as “testers”) can be used concurrently, with each tester testing one DUT at the same time. This would effectively reduce the per-DUT test time by 80%. However, this increased number of testers significantly increases capital equipment costs, thereby diminishing or negating any cost savings for reduced test time. Further, many DUTs may share a test point (e.g., an input/output signal port) between two or more RATs, thereby making it difficult to test the individual RATs simultaneously, since each RAT may require use of one or more different signal characteristics, such as signal carrier frequency, modulation frequency, modulation type, data rate, etc. Lastly, testing different RATs rarely require similar test times. Hence, at least some portion, if not a significant portion, of a test system will remain idle during testing of different RATs.
One technique for minimizing test equipment costs while reducing overall test time is to use a tester having a single VSA and single VSG with a switching subsystem that can switch the VSA and VSG among multiple input/output (I/O) signal ports such that multiple DUTs can be tested substantially concurrently, though not exactly in parallel, since the single VSA cannot capture and analyze transmitted signals from multiple DUTs concurrently. Alternatively, resource sharing can include use of a common I/O signal port, where possible, and switch among the multiple DUTs. While such systems using switching subsystems and sharing resources can maintain reduced test equipment costs, reductions in test time can be better realized using a system with a VSA and a VSG for each DUT signal port, though at significantly higher test equipment cost.